The present invention is directed to devices useful in osteoplastic surgical procedures. More particularly, the invention is directed to a drill alignment guide which is useful in the revision of a total hip replacement.
As a result of advancements in medical technology, the surgical replacement of dysfunctional joints has become common. One such surgical replacement operation, referred to as a total hip replacement, is performed on the ball and socket joint of the hip. However, the long term success of these total hip replacements has been limited because the active life span of the artificial joint recipient often exceeds the life span of the artificial joint itself. Thus, for the recipient to lead a normal life, it is often necessary to perform a revision, i.e. replacement, of the artificial hip joint.
In the course of revision surgery, it is necessary to remove the worn ball joint and its supporting shaft, from within the intramedullary canal of the femur. The cement material used to anchor the shaft of the original replacement ball to the femur must be removed from the intramedullary canal as well. Typically, the cement is broken up and removed by axially drilling within the intramedullary canal. During such drilling procedures, it is important that the drill be properly aligned and guided to avoid accidental perforation of the cortex of the femur.
There are at least two techniques which are utilized in the prior art to guide the drill within the intramedullary canal. One such technique simply is to guide the drill manually by estimating the location of the drill burr in relation to the center of the intramedullary cortex. When the drill is guided by this freehand technique it is quite possible that the cortex could be accidentally perforated. Fluoroscopy is another technique which is used to guide the drill along a predetermined path in order to avoid unexpected damage to the femur. This technique is disfavored, however, as it may expose the patient to a high dosage of radiation. Also, the typically large size of the fluoroscopy equipment may occupy too much space and may compromise the sterility of the operating room.
Accordingly, it is an object of the present invention to provide an apparatus which accurately guides a drill along a path within the intramedullary canal of a femur. A further object of the invention is to provide a drill alignment apparatus which may be safely and conveniently used in a surgical environment. Other objects of the invention will be apparent to those having ordinary skill in the art upon reading the present disclosure.